/* var aaa = 111;
var btn = function(){
	var bbb=555;
	console.log(aaa);
	
	
	var aaa;
	console.log(aaa);
	var click2 = function(a){
		
		console.log("a:"+a+"  b:"+bbb);
		a+=bbb;
		//var bbb;
		return a;
	}
	var c = 123;
	console.log(click2(aaa));
} */
/* console.log = (function(){
		let s = console.log;
		console.log(this);
		 return function(str){s.call(s,"hello:"+str);}
})();

function btn(){
	

console.log("userName");
}

function foo() {
	function bar(a) {
	i = 3; // 修改for 循环所属作用域中的i
	console.log( a + i );
	}
	
	for (var i=0; i<10; i++) {
	bar( i * 2 ); // 糟糕，无限循环了！
	}
}
 */


/*  var ss = function(){
	 console.log('ss is running...');
	 return 'ssss';
 } 
  console.log(ss()); */

/*  (function(){
	 function foo(){
		 console.log('this is foo');
	 };
	 foo();
 })();
 
 foo(); */
/*  
 setTimeout(function(){
	 console.log('this is setTimeout');console.log(ss);}
	 
 ,1000); */

console.log(a);
a = 2;
console.log(a);
var a;
console.log(a);

console.log(b);
var b = 3;


 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
